“Residual Effect of Sheep Manure on Lettuce Cultivation at Different Spacings”. Revista Verde de Agroecologia e Desenvolvimento Sustentável 12, no. 3 (July 1, 2017): 508–511. Accessed September 12, 2026. https://www.gvaa.com.br/revista/index.php/RVADS/article/view/4901.